Lubricated plug valve



Feb. 25, 1941.

s. J. NORDSTROM LUBRICATED PLUG VALVE Filed Sept. 15, 1958 3 Sheets-Sheet 1 III" ATTOR1 EY.

I NV E NTOR.

Feb. 9 I s J. NQRDsTmSM 2, 33,220

LUBRICATED PLUG V ALVE i Filed Sept. 15, 1958 s Sheets-Sheet s Patented Feb. 25, 1941 LUBRICATED ewe verve Sven .l. Nordstrom, Lafayette, Calif assignor to Merco Nordstrom Valve Company, ittsburgh, Pa., a corporation of Delaware Application September 15, 1938, Serial No. 230,105

6 Claims.. (or. 251-493) This invention relates to plug valves of the type having provision for applying viscous lubricant under pressure to certain parts thereof, It has particular application to such valves having ta- 5 pered plugs, and which employ the compressed lubricant to hydraulically jack the plug from its seat.

This application is a continuation in part of my application for Plug valve, filed June 1, 1931, 0 Serial No. 541,218, new Patent 2,029,438, granted Feb. 4, 1936, and of my application for Plug valve, filed November 26, 1935, Serial No. 51,690.

The lubricant system employed according to the present invention involves an arrangement of longitudinal lubricant conducting grooves in the plug surface, some of which are at all times connected to the source of lubricant pressure and which communicate with a lubricant chamber at ,the smaller end of the plug, the other grooves being disconnected from the source of lubricant pressure only when exposed to line fluid. The larger end of the plug is sealed by a circumferential groove which communicates with the reservoir only in certain positions of the plug. Where the size of the valve is small enough, the smaller end of the plug is sealed by the lubricant chamber, or in larger valves a circumferential groove is provided at the smaller end. Preferably, the lubricant grooves are arranged to form a substantially complete lubricant seal about the valve passage in closed position of the valve.

Accordingly, it is an object of the invention to increase .the effectiveness and efiiciency of the lubricant system in plug valves.

It is a further object of the invention to provide plug valves with a novel lubricant system therein that enables hydraulic jacking of the'plug with respect to its seat and lubrication and sealing of the valve working surfaces in a more efficient manner than heretofore experienced.

It is another object of the invention to provide a new arrangement or form of lubricantchannels interrupting the valve working surfaces of a plug valve utilizing lubricant under pressure, whereby the advantages of sealed port lubrication can be secured without an undue washing away of the lubricant in certain channels which (are exposed to the line pressure when the plug is turned between open and closed positions.

Further objects of the invention will .appear from the following description, in which the preferred embodiments of the invention are set forth in detail in conjunction with the accompanying drawings, wherein:

Figure 1 is a view in vertical cross section of a valve incorporating the present invention,

Figure 2 is a plan view of the casing shown in Figure 1, with the cover and plug removed,

Figure 3 is a cross sectional view of the plug taken along the line III-111 of Figure 1,

Figure 4: is a view in vertical cross section illustrating a modified form of plug valve incorporating the present invention,

Figure'5 is a fragmentary sectional view of the casing similar to Figure 4 with the plug removed,

Figure 6 is aview in cross section illustrating a modified form of plug valve incorporating the present invention,

Figure 7 is a cross sectional view of the plug taken along the line VIIVII of Figure 6,

- Figure 8 is a cross sectional detail taken alongthe line VIII-VIII- of Figure 6,

Fi u e 9 is a view in cross section illustrating a further modification of my invention, and Figure 10 is a cross sectional detail taken along the line X-X of Figure 9.

Referring first to the modification illustrated in Figures 1 to 3 inclusive, the valve shown therein comprises a casing it having a transverse passageway H for flow of fluid and a tapered valve seat or bore 52 extending transversely to the pas sageway H. A tapered plug it is rotatably positioned within the valve seat I2 and has a port 14, adapted to register with passageway for open position of the valve. A stem it, operably connected to the large end of plug i3, is provided for turning the plug. The arrangement of sealing washers and packing rings is substantially like that illustrated in my Patent No 781,321, issued November 18, 1930,and [as it forms no part of the present invention, it will 'not be described here.

The lubricating system of the valve comprises a reservoir la in the stem of the valve which is threaded and receives a lubricant compressing screw IS, a suitable check valve being provided in this chamber, if desired, to prevent refluxing of lubricant or escape of line fluid. The end of reservoir 18 communicates with a substantially diametrical bore 2! extending through the valve,

and lubricant grooves 22 and 23 in the plug surface connect the ends of the bore 2 I with a chamber 24 provided at the smaller end of the plug.

Above the diametrical bore 2| is a circumferential cient length so as to communicate with longitudinal plug grooves 22 and 23 when longitudinallyshort of the lubricant chamber 24.

The operation of the lubricating system for the valve is as follows:

'When the valve is in closed position, as shown in Figure 1, lubricant is supplied from the reservoir l8 through the diametrical bore 2| and is forced through longitudinal grooves 22 and 23 to the lubricant chamber 24 at the smaller end of the plug. Lubricant is also supplied through the dwarf grooves 21 and 29 to the. circumferential grooves 25 and 26 in the plug and body, and by dwarf grooves 28 and 29 to the short longitudinal grooves 3| and .32, respectively. Thus, the'lubricant in grooves 22 and 23 and in circumferential grooves 25 and 26 is under greater pressure than the lubricant in chamber 24 when the plug is jacked from its seat because of the viscous nature of the lubricant so that lubricant is extruded from the grooves and prevents the entrance of foreign material between the plug and seat. The chamber 24 preferably is located in the same distance from the edge of the plug port as the longitudinal grooves, but may be located at a distance as much as about twice the space between the grooves 22, 23 or 3|, 32 and the edge of the plug port l4. As the groovesare located in .the plug surface, they can be machined relatively narrow so "that they will have the desired cross sectional area and will present a relatively small surface to line'fluid so that lubricant cannot be easily washed or blown therefrom by line fluid when the grooves are in exposed position. The longitudinal grooves 22,- 23, 3| and 32 in the plug preferably have a radial depth substantially equal to the width of the groove along the plug surface.

Furthermore, by locating the exposed grooves in the plug they are removed from direct impingement of line fluid when the valve is in partly open position.

In turning the valve to open position the plug is turned counterclockwise as viewed in Figure 3,

so that grooves 3| and 32 are disconnected from dwarf grooves 28 and 38, and remain disconnected while these grooves are exposed to line fluid. exposed or intermediate position, lubricant cannot escape from the system into the line and line fluid cannot enter the system to wash out the lubricant therefrom. A suitable stop is provided to limit rotation -'of the valve to ninety degrees. and in open position grooves 3| and 32 connect with dwarf grooves 21 and 29 while grooves 22 and 23 connect with dwarf grooves 28 and 30.

In the modification shown in Figures 4 and 5. wherein like parts are correspondingly numbered to agree with Figures 1 to 3,-the plug 43 has a circumferential groove 44 adjacent the smaller and, and a circumferential groove 45 located directly opposite in the casing which has four dwarf grooves 46 extending upwardly therefrom. Longitudinal grooves 22 and 23 in the plug connect v 32, 3| terminate short of circumferential grooves 25 and 44 and are arranged to communicate with dwarf gro0ves'2'l, 28, 29 and 30 and 46 when aligned therewith. Four dwarf grooves 5| or any other suitable groove arrangement connect cirber 24. This construction is of particular valuein large valves wherein the chamber 24 is too far removed from the passageway U to the valve so that lubricant therefrom provides an insufficient seal for the lower end andan auxiliary chamber in the form of the circumferential grooves 44 and 45 is desirable. The grooves 22 and 23 in this modification communicate at all times with the chamber 24 by reason of their connection with the circumferential groove 44 which communicates at all times with chamber 24 through connecting grooves 5|.

In the modification illustrated in Figures 6 to 8 inclusive, the valve casing 56 is provided with a tapered valve seat 51 arranged transversely of the fluid passageway 58. Tapered valve plug 59 is packing 64, and this packing in turn forces the inner peripheral portion of diaphragm 82 into engagement with the annular shoulder 61 formed upon the valve plug 59. The lubricating system of the valve includes a threaded bore 89 extending axially of stem 6|, into which the lubricant pressure screw 1| is threaded, and the tapered plug 58- is provided with longitudinal channels 88 and 8|, interrupting its periphery, the channels 88 communicating at their lower end with lubricant chamber 13 and being connected at their upper ends to the lubricant reservoir or chamber 69 by radial duct 83 extending through the plug and connected with bore 69. The lower ends of channels 8| stop short of the small end of the plug and are adapted to communicate with chamber 13 throughconnecting dwarf grooves 18 'formed in the lower portion of the valve seat.

in a counterclockwise direction. In turning the ,plug channels 8| are exposed to the line fluid, but .at this time they are cut off from the lubricant chamber 13 so that lubricant cannot escape therefrom into the line. In full open and closed positions all of the channels 88 and 8| are in comvmunication with chamber 13 so that the valve passage is substantially completely sealed by lubricant chamber 13 and grooves 80 and 8 I. The larger lubricant channels 80- serve to effectively transmit the lubricant pressure to chamber 13, without undue lag or loss in pressure.

In the modification illustrated in Figures 9 and l0, arrangement of lubricant channels in the valve working surfaces consists of four spaced longitudinal channels I6 formed in the periphery of the plug 59 and terminating short of the ends of the plug. Formed in the lower portion. of the tapered valve-seat are four spaced longitudinal channels 18 for full open and closed positions of the plug, and which also communicate at all times with lubricant chamber 13. A lubricant duct 12 extends downwardly through plug 59, the end of this duct communicating with and forming a part of bore 69, and the lower end of the duct communicates with the lubricant chamber 13,

In operating the valve the screw H is turned in sufllciently to develop lubricant pressure in chamber 13 to jack the plug from its seat. Leakage past the small end of the plug and around the sides of the plug is prevented by lubricant extruded from chamber 13 and channels l6 and 18. In intermediate positions of the plug the two exposed channels 15 are cut off from communication with the connecting grooves 18, thus preventing washing out of lubricant from the remainder of the lubricant system. In this construction it is not necessary to prevent rotation of the plug through more than 90, so that no stop is required.

The invention may be embodied in other .specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a plug valve, a casing having a passageway therethrough for flow of fluid and a tapered bore formed transversely of said passageway, a stem for operating said valve, a tapered plug having a port therethrough seated in said bore, said valve having a lubricating system comprising a lubricant chamber at the smaller end of the plug, at least one pair of longitudinal lubricant grooves in the plug surface at opposite sides of the port terminating short of the larger end of the plug, one-groove of said pair connecting at one end with the lubricant chamber at all positions of said plug, a reservoir in the valve stem for supplying lubricant under pressure to said latter groove, a circumferential groove in the seat spaced from the largerend of the plug spaced from the adjacent ends of the longitudinal grooves of said pair, and individual short grooves in said seat communicating said circumferential groove with the longitudinal grooves of said pair at their ends opposite the lubricant chamber in full open and closed positions of the I valve only.

2. In a plug valve, a casing having a passageway therethrough for flow of fluid and a tapered bore formed transversely of said passageway, a stem for operating said valve, a tapered plug having a port therethrough seated in said bore, said valve having a lubricating system comprising a lubricant chamber at the smaller end of the plug, a circumferential lubricant groove in the seat spaced from said chamber and having at least one connecting groove to said chamber, a mating circumferential groove in the plug surface, at least one pair of longitudinal lubricant grooves in the plug surface terminating short of the larger end of the plug, one groove being in communication with the circumferential groove in the plug surface, and said circumferential groove in the seat having connecting grooves connecting with the longitudinal grooves in full open and closed positions of the valve, and a circumferential groove in the seat at the-,opposite end of the plug spaced from the end and having longitudinal extensions communicating with the longitudinal grooves in full open and closed positions of the valve, and means for supplying lubricant under pressure to the longitudinal grooves.

3. In a plug valve, a casing having a passage-' 5 way therethrough for flow offluid and a tapered bore formed transversely of said passageway, a stem for operatingsaid valve, a tapered plug having a port therethrough seated in said bore, said valve having a lubricating syst ing a lubricant jacking chamber formed by the casing and smaller end of the plug, a pair of diametrically opposed longitudinal lubricant grooves in the seating surface of the plug and easing constantly in communication with said 15 jacking chamber and terminating short of the larger end of the seating surface of the plug and easing, each groove being located adjacent one side of the port so as to be unexposed in normal rotation of the plug, a reservoir in the valve plug and casing uniformly spaced from the larger end of the plug and spaced from the adacent ends of said pairs of longitudinal grooves, short longitudinal grooves in' said seating surface individually connecting said circumferential groove with said longitudinal grooves at fully open and fully 34 closed positions of the valve only, and means for applying pressure to lubricant in said reservoir to separate the surfaces of the plug and seat and lubricate said surfaces.

4. In a plug valve, a casing having a passage- 4i way therethrough for flow of fluid and a tapered bore formed transversely of said passageway, a stem for operating said valve, a tapered plug haw ing a port therethrough seated in said bore, said valve having a lubricating system comprising a 4 lubricant chamber at the smaller end of the plug, a circumferential lubricant groove spaced from said chamber interrupting the seating surface of the plug and seat and having at least one connecting groove to said chamber, at least one 5| longitudinal lubricant groove interrupting the seating surface of the plug and seat and terminating short of the larger end of the plug and being in communication with said circumferential groove at all times, at least one other longi- 6 tndinal lubricant groove in the plug surface terminating short of the larger end of the plug and terminating short of the smaller end of the plug, said. circumferential groove having connecting grooves connecting with said other longitudinal 6 groove in full open and closed positions of the valve, a second circumferential groove at the larger end of the plug interrupting the seating surface of the plug and seat beyond the adjacent ends of said longitudinal grooves, short longitudi- 6 nal grooves interrupting said seating surface and communicating said second circumferential groove with said above mentioned longitudinal grooves in full open and closed positions of the valve, and means for supplying lubricant under 7 pressure to the lubricating system.

5. In a plug valve, a casing having a passageway therethrough for flow of fluid and a tapered bore transversely of the passageway, a tapered plug having a port therethrough seated in said 7 comprism bore, a lubricant jacking chamber between the casing'and the smaller end of the plug, a first pair of diametrically opposite longitudinal .grooves on said plug terminating short of the larger end of said plug but connecting at one end with said' chamber at all positions of said plug,

a second pair of diametrically opposite longitudinal grooves on said plug terminating short of the larger end of said plug and also terminating short of the smaller end of said plug, an unint'errupted circumferential groove on the larger end of the plug beyond the adjacent longitudinal groove ends, an opposed uninterrupted circumferential groove on said seat open to said circumferential groove on the plug. four short longitudinal grooves on said seat communicating said-circumierential grooves with said pairs of longitudinal grooves in fully open and fully closed positions of the valve only and means supplying lubricant under pressure to said grooves.

. 6. In the plug valve defined in claim 5, said last-named means comprising a valve stem on said plug, a lubricant reservoir in said stem, and radial passages in said plug connecting said reservoir to the ends of said first pair of longitudinal grooves at the larger end of said plug.

SVEN J. NORDSTROM.

CERTIFICATE OF CORRECTION.

Patent No.'2,255,220. February 2 19in;

SVEN J. NORDSTRO'N.

, It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second column, line 55, for the patent nmnb er-" 7EI 821" run -1,781,821; age 2, first column, line 65L'fbguand" first oocfirrence, read --end-; page 5, first column, line h6, c lai'm 1, after "-plug" insert "and"; and that the said Letters Patent should be read with this oorrection therein that the same may conform to the reoord of 'the Case, in the Patent Office.

Signed and sealed this ZOthQday of May, A D. l 'l 9 hl'.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

